static VALUE method_geometry_disjoint(VALUE self, VALUE rhs)
{
VALUE result;
RGeo_GeometryData* self_data;
const GEOSGeometry* self_geom;
const GEOSGeometry* rhs_geom;
char val;
#ifdef RGEO_GEOS_SUPPORTS_PREPARED2
const GEOSPreparedGeometry* prep;
#endif
result = Qnil;
self_data = RGEO_GEOMETRY_DATA_PTR(self);
self_geom = self_data->geom;
if (self_geom) {
rhs_geom = rgeo_convert_to_geos_geometry(self_data->factory, rhs, Qnil);
if (rhs_geom) {
#ifdef RGEO_GEOS_SUPPORTS_PREPARED2
prep = rgeo_request_prepared_geometry(self_data);
if (prep)
val = GEOSPreparedDisjoint_r(self_data->geos_context, prep, rhs_geom);
else
#endif
val = GEOSDisjoint_r(self_data->geos_context, self_geom, rhs_geom);
if (val == 0) {
result = Qfalse;
}
else if (val == 1) {
result = Qtrue;
}
}
}
return result;
}
/*
* Return whether the given line segment is suitable as an
* approximation of the projection of the source line.
*
* t_start: Interpolation parameter for the start point.
* p_start: Projected start point.
* t_end: Interpolation parameter for the end point.
* p_start: Projected end point.
* interpolator: Interpolator for current source line.
* threshold: Lateral tolerance in target projection coordinates.
* handle: Thread-local context handle for GEOS.
* gp_domain: Prepared polygon of target map domain.
* inside: Whether the start point is within the map domain.
*/
bool straightAndDomain(double t_start, const Point &p_start,
double t_end, const Point &p_end,
Interpolator *interpolator, double threshold,
GEOSContextHandle_t handle,
const GEOSPreparedGeometry *gp_domain,
bool inside)
{
// Straight and in-domain (de9im[7] == 'F')
bool valid;
// This could be optimised out of the loop.
if (!(isfinite(p_start.x) && isfinite(p_start.y)))
{
valid = false;
}
else if (!(isfinite(p_end.x) && isfinite(p_end.y)))
{
valid = false;
}
else
{
// TODO: Re-use geometries, instead of create-destroy!
// Create a LineString for the current end-point.
GEOSCoordSequence *coords = GEOSCoordSeq_create_r(handle, 2, 2);
GEOSCoordSeq_setX_r(handle, coords, 0, p_start.x);
GEOSCoordSeq_setY_r(handle, coords, 0, p_start.y);
GEOSCoordSeq_setX_r(handle, coords, 1, p_end.x);
GEOSCoordSeq_setY_r(handle, coords, 1, p_end.y);
GEOSGeometry *g_segment = GEOSGeom_createLineString_r(handle, coords);
// Find the projected mid-point
double t_mid = (t_start + t_end) * 0.5;
Point p_mid = interpolator->interpolate(t_mid);
// Make it into a GEOS geometry
coords = GEOSCoordSeq_create_r(handle, 1, 2);
GEOSCoordSeq_setX_r(handle, coords, 0, p_mid.x);
GEOSCoordSeq_setY_r(handle, coords, 0, p_mid.y);
GEOSGeometry *g_mid = GEOSGeom_createPoint_r(handle, coords);
double along = GEOSProjectNormalized_r(handle, g_segment, g_mid);
if(isnan(along))
{
valid = true;
}
else
{
valid = 0.0 < along && along < 1.0;
if (valid)
{
double separation;
GEOSDistance_r(handle, g_segment, g_mid, &separation);
if (inside)
{
// Scale the lateral threshold by the distance from
// the nearest end. I.e. Near the ends the lateral
// threshold is much smaller; it only has its full
// value in the middle.
valid = separation <= threshold * 2.0 *
(0.5 - fabs(0.5 - along));
}
else
{
// Check if the mid-point makes less than ~11 degree
// angle with the straight line.
// sin(11') => 0.2
// To save the square-root we just use the square of
// the lengths, hence:
// 0.2 ^ 2 => 0.04
double hypot_dx = p_mid.x - p_start.x;
double hypot_dy = p_mid.y - p_start.y;
double hypot = hypot_dx * hypot_dx + hypot_dy * hypot_dy;
valid = ((separation * separation) / hypot) < 0.04;
}
}
}
if (valid)
{
if(inside)
valid = GEOSPreparedCovers_r(handle, gp_domain, g_segment);
else
valid = GEOSPreparedDisjoint_r(handle, gp_domain, g_segment);
}
GEOSGeom_destroy_r(handle, g_segment);
GEOSGeom_destroy_r(handle, g_mid);
}
return valid;
}
